The present invention concerns support of advanced intelligent network (AIN) services in voice frame networks using protocols such as voice over Internet protocol (VoIP) based upon the ITU-T 450.1 standard, which is the supplementary services protocol framework within ITU-T H.323 networks.
AIN is the Bellcore term for such intelligent network services, and Intelligent Network (IN) is the ITU-T term. Both terms convey the idea of a network that provides a platform to deploy user services in a fast and efficient manner. Since they are very similar in the services they provide and the network architectures, the term AIN is used through this patent application. However, the present invention can be used for both AIN and IN without any modification.
A fundamental aspect of AIN is the ability to support the quick creation of services for the end customer. The AIN uses technology of Signaling System number 7 (SS7) and adds its functionality at the application layer to achieve goals like:                1) Provide timely creation of new services for the customer;        2) Support a wide range of services;        3) Support efficient maintenance of the AIN system;        4) Enforce a seamless environment between vendors' systems; and        5) Automate services that entail operator intervention.        
One of the most important AIN network elements to achieve these goals is the service control point (SCP). It contains Service Logic Programs (SLPs) and associated data to provide AIN services, such as 800 numbers, credit verification, and so on. Sometimes, the services provide by the SCP are also called supplementary services in order to differentiate the basic call services provided by the switch services point or SSP, another important AIN network element. The SSP is responsible for basic call processing operations and the switching operations to move the signaling traffic through the network. The SSP uses the signaling traffic to set up a connection. The basic call services include call origination authorization, dialed address information collection and analysis, and so on.
A related AIN application is the provision in a voice frame network of an interface between an intelligent peripheral such as an interactive voice response unit and a gatekeeper. Such an interface based on ITU H.323 and H.450 is described in co-pending U.S. patent application Ser. No. 09/609,201, filed Jun. 30, 2000 entitled VOICE FRAME NETWORK GATEKEEPER-TO-INTELLIGENT PERIPHERAL INTERFACE METHOD AND APPARATUS. The co-pending patent application is assigned in common with the present application to Cisco Technology, Inc. and its disclosure is incorporated herein by this reference.
Those of skill in the art will appreciate that the referenced ITU and related standards are well known, evolving standards. Accordingly, reference herein to these standards will be understood to mean the standards as they existed at the time of the earliest effective filing date of the present application, and as they have evolved to date, and as they continue to evolve over the term of any patent that issues herefrom. Applicants note that an instructive earlier version of the ITU H.450.1 standard is described in Generic functional protocol for the support of supplementary services in H.323, date unknown, and that various ones of the ITU-T standards are described in Call Signaling Protocols and Media Stream Packetization for Packet Based Multimedia Communications Systems, February 1998 and Call Transfer Supplementary Service for H.323I, September 1997.
FIG. 1 shows the conventional AIN architecture wherein one or more SSPs 10a, 10b are connected via a generic interface 12 to a SCP 14 having a database 16 connected therewith. SCP 14 will be understood by those of skill in the art to provide one or more supplementary services via so-called service logic programs (SLPs) and needed control data for implementing desired SCP functions, as are known. SSPs 10a, 10b will be understood by those of skill in the art to provide call switching and routing functions as well as basic call services, as are also known.
Instead of tailored messages for a specific service, the AIN architecture uses a common set of standardized messages for a variety of services. Thus, the switch call processing and the SCP database processing support a common interface to, for example two different SSPs, as shown in FIG. 2. FIG. 2 is similar to FIG. 1 and further shows the routing via dashed lines of various message components among SSPs 10a, 10b, SCP 14, a calling party 18 and a called party 20.
A typical AIN session proceeds as follows (wherein the numbers on the dashed lines in FIG. 2 correspond with the numbered steps below):                1) A calling party dials in to network.        2) SSP makes query to SCP on a common interface, such as SS7 (in 800 number service, SSP sends query to SCP to get routable address information).        3) SCP returns the replay that contains the requested information (in 800 services, SCP returns the SSP with a number, such as 949-823-1146, and the SSP uses its call processing to route the call).        4) SSP associated with the calling party sets up the connection to the SSP associated with a called party.        5) The terminating SSP sets up the connection to the called party.        
As mentioned above, both Bellcore AIN and ITU-T IN services are deployed by SS7 networks. More precisely, the SS7 TCAP (Transaction Capabilities Applications Part) is the protocol that carries the common set of standardized messages of AIN services between a SCP and one or more SSPs.
FIG. 3 illustrates the conventional protocol architecture 34 for TCAP-based SCP by which the TCAP transaction and component and processing as layers over the SS7 network provides a TCAP message handling interface 46 between the AIN 0.1/0.2 protocol and message set 44 and application processes 42 and the SS7 network and SCCP/MTP protocol 48. Those of skill in the art will appreciate that TCAP functions are grouped into two portions: a transaction portion 50 and a component portion 52.
The transaction portion 50 identifies whether the TCAP transaction is expected to include single or multiple messages and provides an application-level associated over which components are exchanged. Also, the transaction portion 50 provides a way to indicate whether its content is the only message in this exchange or the portion of the message in an extended exchange of information (i.e., first, middle, last). This is necessary in SS7 networks since a SS7 message can not exceed 272 bytes. If a SS7 message for an AIN service contains more than 272 bytes, it will be broken into more than one piece, with each piece being fitted into one SS7 message.
An understanding of the AIN architecture and services leads to the conclusion that the SCP functionality is independent of the basic call services provided by the SSP, as long as both SCP and SSP access through a common interface. In other words, the supplementary services provided by SCP can be used to serve for other network architectures, such as ITU H.323 networks to provide same voice services as SSPs in a public switched telephone network (PSTN) context. This is the inspiration for an invention that provides AIN services in ITU H.323 networks by using a SCP, a SCP based on ITU H.450.1, the supplementary services protocol framework in ITU H.323 networks.